Field of the Invention
The present invention relates to a vehicle seat.
Related Art
In a vehicle seat described in Japanese Patent Application Laid-Open (JP-A) No. 2009-107571, a pad member (seatback pad) of a seatback is supported from the seat rear side by a plane spring structure (lattice-shaped spring member). The lattice-shaped spring member is formed by wires arranged in a lattice shape, and is coupled to a seatback frame by connecting wires. The lattice-shaped spring member resiliently supports the seatback pad from the seat rear side, thereby enabling the comfort (ride comfort) of a seated occupant to be secured during normal operation.
In the event of a collision from the rear (rear collision), load from the seated occupant moving toward the seat rear side under inertia is input to the lattice-shaped spring member, releasing the coupled state between the lattice-shaped spring member and the connecting wires, or the coupled state between the connecting wires and the seatback frame. The back and lumbar of the seated occupant accordingly enter the seatback, and the head of the seated occupant is swiftly supported by a headrest. Whiplash injury can accordingly be reduced, contributing to an improvement in occupant protection performance.
Recently, some seatback frames are being formed entirely out of resin, with the intention, for example, of reducing the weight of the vehicle seat. Improvements in occupant protection performance in the event of a rear collision, while securing the comfort of the seated occupant during normal operation, are also demanded in vehicle seats provided with such resin seatback frames.